Perhaps you should try some spelling variations:
te sach » toc sach
hanh va » hang va
luc van » luoc van, luu van, duc van
cao luc » bao luc, cao duc, cao suc
su tien » su kien, su hien, tu tieng
hieu va » lieu va, hieu qua
su dang » su dung
vu dang » vu quang, cua dang
va cao » va cac, va co, va dao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((vu dang) OR (su dang)) xa hoi. hieu va cao luc van ((hanh va) or (hanh vi)) su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((vu dang) OR (su dang)) xa hoi. hieu va cao luc van ((hanh va) OR (hanh vi)) su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((vu dang) OR (su dang)) xa hoi. hieu va cao luc van ((hanh va) or (hanh vi)) su tien".
• Adding a wildcard symbol may retrieve word variants: te sach ((vu dang) OR (su dang)) xa hoi. hieu va cao luc van ((hanh va) or (hanh vi)) su tien*.